36 lines
837 B
Plaintext
36 lines
837 B
Plaintext
|
tokens:
|
||
|
|
\s+ # Do nothing
|
||
|
|
( OPEN_PAREN
|
||
|
|
) CLOSE_PAREN
|
||
|
|
{ OPEN_CURL
|
||
|
|
} CLOSE_CURL
|
||
|
|
+ ADD
|
||
|
|
- SUB
|
||
|
|
* MUL
|
||
|
|
/ DIV
|
||
|
|
= EQUALS
|
||
|
|
, COMMA
|
||
|
|
; SEMICOLON
|
||
|
|
"[^"]*" STRING
|
||
|
|
def DEF
|
||
|
|
return RETURN
|
||
|
|
\d+ NUMBER
|
||
|
|
\w+ IDENT
|
||
|
|
grammar:
|
||
|
|
program: block
|
||
|
|
block: { statement }
|
||
|
|
statement: IDENT EQUALS expression SEMICOLON # ident=expression; : x=10;
|
||
|
|
| DEF IDENT OPEN_CURL block CLOSE_CURL # def ident { block } : def hi{return 10}
|
||
|
|
| RETURN expression SEMICOLON # return expression; : return 10;
|
||
|
|
| expression SEMICOLON # expression; : 1+2;
|
||
|
|
expression: term { addop term } # 1+2-3+400-67...
|
||
|
|
term: factor { mulop factor } # 7*3*67/4*8*3...
|
||
|
|
factor: IDENT OPEN_PAREN CLOSE_PAREN # ident() : hi()
|
||
|
|
| IDENT # ident : hi
|
||
|
|
| OPEN_PAREN expression CLOSE_PAREN # (expression): (1+2)
|
||
|
|
| SUB NUMBER # -number : -10
|
||
|
|
| NUMBER # number : 10
|
||
|
|
| STRING # string : "hi"
|
||
|
|
addop: ADD | SUB
|
||
|
|
mulop: MUL | DIV
|